The law's good faith principle has traditionally regulated legal relationships, such as the contractual relationship. Equity's more intense fiduciary principle has generally regulated equitable relationships, such as the trustee-beneficiary relationship. Now comes the Uniform Trust Code, specifically § 105, and provides that “the terms of a trust prevail over any....[of the Code's provisions]... except…the duty of a trustee to act in good faith…” This provision is “echoed” in § 801 (Duty to Administer Trust). What is one to make of this? The official commentary is devoid of any explanation. Could we be seeing here a stealth retirement of the fiduciary principle when it comes to the regulation of trusteeships? Or is this just a gratuitous muddling and conflating of nomenclature?

Charles E. Rounds, Jr., et al. speculate in §8.15.81 of Loring and Rounds: A Trustee’s Handbook, at page 1237 of the 2014 edition. See also § 3.5.3.2(a) [page 182 of the 2014 edition]. Section 8.15.81 is reproduced in its entirety here.